#include<stdio.h>
#include<stdlib.h>
#include<string.h>


void verificaRA(char *str){

char* aux;
int i;
aux = str;

for(i=0;i<6;i++){

	if(isdigit(str[i]) == 0){
			printf("Erro! O RA deve possuir somente caracteres numericos\n");
			return;
	}
	
}

str = aux;

return;

}

int main(){

char string[7];

fgets(string, 7 	, stdin);

verificaRA(string);

printf("%s\n", string);

return 0;
}